Synthesis and Antimicrobial Activity of New Dihydropyrazolo[1,5-a]pyrimidine Derivatives

Objective: To synthesize new dihydropyrazolo[1,5-a]pyrimidine derivatives and screen for the antibacterial and antifungal screening. Methods: We have synthesized a new series of 7-(1,3-diphenyl-1-H-pyrazol4-yl)-2-(methylthio)-5-oxo-4,5-dihydropyrazolo[1,5-a]pyrimidine-3,6-dicarbonitrile compounds and screened compounds for antibacterial and antifungal activity. Gram-positive (Bacillus megaterium, Micrococcus spp.) and Gram-negative bacteria were tested for antibacterial activity (E.coli, S. typhi). Antifungal activity was tested on Ganoderma spp., A. niger, A. flavus, and Penicillium spp. Results: Some compounds have shown significant antimicrobial activity. Discussion: As per the results the compound possesses good biological activity due to presence of core pyrazolo[1,5-a]pyrimidine moiety. Conclusions: The synthesis of new 7-(1,3-diphenyl-1-Hpyrazol-4-yl)-2-(methylthio)-5-oxo-4,5-dihydropyrazolo[1,5-a]pyrimidine-3,6-dicarbonitrile compounds was successfully completed and characterized by relevant techniques. Compounds are screened for the biological activities with moderate to good results. The MIC of the synthesized compound is compared to marketed available standard drugs.